Thread-cutting mechanism for sewing-machines.



'APPLICATlOfi FILED APR. 18. I918.

I Patented Jan. I, 1919.

.l V! W m H W .L 0 J m W T n m M k m w 6 7 S xv V. v

. 4 EU 2 W :1 I B ymja A. R. W000. THREAD CUTTING MECHANISM FOR SEWINGMACHINES.

APPLICATION FILED APR.1B, 1 9L8.

1,291,335. fatenied 1919.

2 sums-snarle- INVENTOR leaflet in order than.

sA'IP irnnfr onisic ALFRED It. W001i, BRIDGEPORT, CONNECTICUT, ASSIGNOB.TO THE SINGER MANU FACTURING *QGMPANY, A CORPORATION OF NEW J ERSEY.

I THREAKl-GUTTING MECHANISM FOR SEWING-MACHINES.

' Application filed April 18,

To alt whom it may, concern lie it l-tnown that l', Amman ll. Woo nacitizen, of the Unit-ed States, residing at lira port, in the county ofFairficld and State of Qonnecticut have invented certain new and usefulimprovements in Thr nd- Uutting h'lecha'nisnis for Sewing-Machines, ofwhich. the following is a specification, rot orence being had therein tothe aecon panying drawings.

This invention relates to thread-eutting ni tihanisni for sewingmachines, more parti iiarly of the buttonhole type employing arccign'oceting needle and lower thread-hen can; inipienicnts mounted ina rotary turret nnd cooperating therewith to form a group ofoverseaining stitches. An object of the invention is to provide animproved mechanism for cutting the needle-thread in a machine of theclass described at a point below the worli' and close to the under sideof the the cut end of needlethi'cad, leading to the iast stitch will beshort and so that a relatively iong length of thread will he left hangifrom the eye of the necdie. to sis-unis the starting of the nextstitching operation.

A. tort-her object of the invention is to pro vicl'e a. slu'eadcuttinn;mechanism paiticulariy adapted for embodiment in machine making theeyic-ot' stitch disclosed in the Un ted States Patent to E. E. Allen No.

-- idniihfhtii, defied June 18, 1912, and which will not interfere withthe movements of the necessary thread-handling iinplemen$ or .hiopersclose to the under surface oi the vvorlc l titill further, the inventionhas for an objest to provide a threachcutting mechanism which will severthe thread with certainty even though the cutting blade should becomeslightly dulled through long; continued use.

li urther objects of the invention will appear from the foilowingdescription and claims.

iough the invention is sumeptibleot: einhoriunent in sewing machines ofvarious types have chosen to illustrate it aseinhodied in the buttcnholesewing machine" oi. lcsed in the application of E, B. Allen, Serial No.179,139, filed July 7, 1917; said machine being fitted withstitch-formin mechanism of the im'roved type disclosed in theapplication of Allen and H. Cl Faulkner, Seriai No. 222,071, filed March13,

Specification of Letters Patent.

'atented Jain tat, 1919.

1918. Serial No. 229,237.

1918. Buttonhole sewing machines of the types disclosed in the saidapplications are commonly provided with buttonhole cutting mechanismwhich operates to cut the buttonhole either before or after thestitching operation, the cutting being accomplished when thestitch-forming iiiccllanisni and the worle holder are dilferentlypositioned relatively to each other than when the machine is stitching.

When the machine has been brought to rest at the end of ahiittonholc-producing cycle, the stitclnforniing mechanism -andwork-holder are in buttonhole cutting position and when theniachinc isagain started the Work is clamped in a new position. If the machine isone that cuts the butt-onhole before stitchii'ig, the buttonholc-ci tternext gnnes into action to cut the buttbnhole-slit after which theWork-holder and stitch-tonning mechanism partake of a relative movementto carry the parts to stitching position. The stitch-forming mechanismis then started an lfduring a further relative stitch-positioningmovement of said stitch-forming 80 mechanism and work-holder, thewerseaniing stitches are placed around the buttonholet if theniachine'is adapted to sew series of radial stitches at the end of thebuttonhole, the stitch-forming mechanism is given a partial rotati 11after the first side of the buttonhole in s en stitched to positionstitches iadially around the end. of the huttonhole. After the second orreturn side of the huttcnhole has been stitched, the stitchformingmechanism ,is Stopped and the I stitch-forming mechanism and work-holderhave a further relative movement to bring the parts to huttonholecutting position again whereupon the machine is brought to rest. ladjustment 0 the time of operation of the stitch-forming mechanism,buttonholes of various lengths may be stitched; the stitch-formingmechanism starting earlier and finishing later to stitch a longerbuttonhole. The total relative travel of the stitcl1-f rrning mechanismand work-holder is fixed for all. lengtl s oi huttonholcs produced bythe machine and slightly exceeds the longest bnttonhole which themachine is designed produce. When the machine is brought to rest it hasheretofore been customary to c it the needle-thread by hand at the upperside of.

the Wonk; the thread extending work, around :1 lower thread-handling inplomnt and b ick to the lust stitch. 'Tho cutting or thei'ioodio-t-lnezu'l above the Work therefore necessitates n considerablewaste of thread since :1 relatively long thread-end is left hanging fromthe nndei side of the Work after it is ICIBOVLKlflOH'I tho machine.

through ihe' Iwioroovor there is danger that the needle,

may become nnthi'eaded due to tho drawing back of the short thread-endhanging from the lnGGLllQ-QYP. it has also been proposed, in a machineof the presPni: character, to out the thread of tho last noodle-loopbelow the work but, in the latter case, the limb of tho needle-loopleading in the needle has been,

out and co'i'isequontly a long and of thread has hoon loft, hangingfrom'tlic work and a short and has been left hanging from thenoodle-eye.

The fox-{going difficulties auto overcome and the ohjocts of theinvention um attained by tho cinployn'mnt of a specially formedtlii'ond'iciiil'iiig blade which is lYlOiHJ-TfllP011 handling;instz'izn'iontalilin which eoiipornlo with the needle. in tliopi'oim'rvdenil odi-- montoi the invvniioin thellnvml-cuiting lihido isankle-shaped and is :l'oimvd at- 51 short dislunvu hack of itstip-endwith :i redm'od noel: iilh'n'dingr ll i-onirwiutdly directed and'shni'pnnvd mailing edge. 'Thohlnde is pivoi'nlly mounted at its-shimivind upon a nmwllv-guidv him-hut, which, in turn, is rigidly ansiuinml in:i 'po iit rising fiom the inn-vi. 'lhv i-ntiiai hizado;i:-;suhsinnt'inlly fiat and is no iiisposvd us toppomio in a substnn.

are "formed iniogrz'iilly with thoslinnk-cnd oftho viillor-hh do undnmshwith uisogn onigal implomon-l's for oRvillntoi'y movomonii'ohi.

lively to said pin. Th4: said iillpi'nni-pin can-non a crank memberwhich is noted npon 'lhzougli Silli'il-lilo minim-lions \Ylllih'?slop-motion which conii'olsiho period of opoz'ntion'oi lhorsliii'h-foi-ming nwvlihn'isni, am lltflllfitil!iQVQ! niounimlnponiliiQiiiiM'liiiiii fi'znnoto swing llUl'i'li-(lllliilihi first unused loongngo and shift, the lover mounted on hnitonhole, the turret i5 not. inposition for the spying-actuated lever momted thereon to be engaged bythomsiuator-lovor.- Assoon as the turret has been rotated the us'g a'l180 in stitching around the end of the bi1ttonhole, the,spring-zict-imted lever is carried into operative position relatively tothe actu :itordovciand is in position to lie shiftod hytheactuator-lover whonovei' the stop-mm iiion is tripped.

In the :iccompanying drnwings, I fi gnro il.

is an nssomljilod. perspective view of the parts of the, huhtonholesowing niavhino irelnting $10 the present invention. Fig. 2 IS a yourpoi'spmtliivo View of tho liaise-portion of the machine showing, thestop-mvvhnnism and the lhroiul-cuttor actuating connections. Fig. 3 is apoi's 'ieoiivo View of the turret for the lowerthrond-lmndlingimplements showcutting and slitvliing machine (llSUlUHlllin the application oi E. B. Allen :iho'i'o iol vl'l'fll to. The1nnchinwfrnniucomprises a hollow llKflilHgIllliU' lmsvfil sustaining thoniuuulnx d 2 and overhanging l'nuu kothrni 3 timinating in the, hollonhead 4 in winch the nevdlvhal 5 is journnlod foi-ii'egipiot-alion. Atits tho lllll'tl; in opposition :fo'its spring,'thorohy :i'wd loverlowiihdmw tho vntmi'dilade to inopm'nin'iposition and in While btiichingdown the first gaido dithewhoRitclnforming A and holds it n s'ii'eadwonditzon in t low'nif. "th road 3 common to ingiohins' (if 'thIStypg 1 Cooperating w th theiphreaddl loope which proje tho cross-11inoi" the nedlo on its"(lonlhk-iihili cent.

(:lss itsloop throngli an owrdg I im-dle-loop, is" a loop-retainer lljllOlll'llfBd on f-i cai-i-wr-lm'e E; a sevond loop-retainerhi8 mountedupon :i mii'i'ior-loi'oi' '19 luhrriimnd to turn'lupon l tho cross-phiill. Tho secondiretainer"18 seizes 2i depth-stitch nuedlaf-lpop from theover-edge descent.

non-threaded looper and holds it in spread condition in the. path of theneedle in its The retainer levers are oscillated simultaneously inopposite directions by means of link connections 15, v19 with across-head 19 formed at the upper end of the usual rising and fallingrod 19" common to mechanisms of the present type. The retainers 14 and18 operate in substantially parallel paths close to the under surface ofthe work and below the usual throatplate or button 20 which is fixed tothe post teeth 25 integral-therewith and is fulcrumed to the nedle-guidebracket 26 .by means of the screw-pin 27 the bracket 26 being fixed tothe top of the post 21 and formed at its free end with theneedle-guiding plate 28 which insures the positioning of the needleforwardly of the paths of movement (if the threaded and non-threadedloopers so that.

it will not be struckby said loopers While the latter are seizingneedle-loops. Thecutting blade is so fulcrumed. that the path ofmovement of its freeend is close to the path of movement of the retainer18 for the depth-stitch needledoop; the beaks or tipends of the retainer18 and thread-cutter y direction.

22 being pointed in substantially the same Meshing with the gear-teeth2515 a segment gear 29 fixed to the cross-pin 16'to one end of Which isfixed a crank-arm 30 slotted gat 31'to embrace a pin 32 fixed to the up-,avardlv extending arm 33 of a three-armed lever fulcrumed at thejunctureot the arms to the post 17 by means of the screw 34.

The depending arm 35 of the three-armedlever is formed with a lateralextension 36 Y which, when the turret is rotated to the position shownin Fig. 3, is in position to be struck by the actuator-lever 37. Stops38,

for the lever-arms 33 and 35 determine "the extreme positions of thecutter-blade 22.

A spring 39 is fixed at its upp'eFend to one of the posts 17 and at itslower end to tliit.

bracket 41 screwed to an inside wall of the base 1 and formed withanapertured guidecar 42 for the forward end ofthe slide-rod .43 therearward endof which is connected to the crank-arm 44 fixed to therock-shaft l5 journaled in'the bracket 46 fixed to'the machine frame. Aspring a? surrounding ear 42 and a collar 48 on said slide-rod,

'urges the latter toward retracted position.

T he actuator-lever 37 is also provided with a spring 49 whichyieldingly maintains said lever in contact with the front end of theslide-rod 43.

The rock-shaft 45 carries another crankarm 49 which extends across thepath of vertical movement of the lateral pin 50 fixed to the usualdownwardly spring-pressed slide-block 51 mounted at the lower end of thestop-motion lever 52 which is fulerumed at 53 .to the machine frame. Asstop-motions of the ty e herein referred to are well known a speci 0description thereof is thought to be unnecessary. These stopmotionscommonly employ a clutch ring 54 which is fulcrumed at 55 to the drivenmem-" ber of the clutch and is formed with an outwardly inclined surfaceportion 56 leading to a stop-notch 57. When the stop-motion lever 52 istripped to stopthe machine the stop-tooth 58 is shifted inwardly to aposition wherein it will be lifted in opposition to the Spring 51 by theeccentric surface 56 of the clutcl-i ring. -When so lifted, the pin 50will lift the crank-arm 49 thereby shifting the slide-rod 43 inopposition to its springer? and causing the actuator-lever 37 to deflectthe lateralr rojection. -36 of the three-armed. cutter-con rolling(lever mounted on the turret. The cutter blade will thus be projectedinto the last needle-loop'l which is held by the retainer 18, as shown1n Fig. 4, the 100 being drawn up snugly about the reduced neck of thecutter by the usual takeu mechanism before the machine comes to rest.When the tooth 58 naps into the stopnotch 57, the pressure of theslide-rod 43 upon the actuatordever 37 will be relieved and, as aresult, the spring 39 will act upon the arm 400i the three-sinned leverto cause the withdrawal of the cutter-blade 22 from full to dotted lineposition,-' Fig. 4, to effeet the serverancefiflthat of the needle-loopwhich-slead's 'tofthelast stitch.

It will be readily appreciated that, by

virtue of the foregoing; construction, the

cutter 22 cannot glanoeb and fail to sever the needle-loop even thoughthe cutting ed ge 24 should become slightly dulled through longcontinued use. v

- The machine i fitted with the usual mechanism for turnlng'theneedle-bar 5 and tarret ll -in fiacing the radial stitches around theend of a buttonhole and for'reversely turning these parts to initialposition after the buttonhole hasbeen stitched or before the nextstitching operatipn.

The vertical shaft" 59 is formed at its its op osite ends withcrank-arms 60 and 61 of su stantially the ame length and connected bymeans of links 62 and 63, respectively, with similar sector-gear levers(lat and 65,

roeating needle and c i meshing with pinionsGfi and 67 which transniitturning movements to the needle-bar and turret, respectively, in theusual manner. The crank-arn'i 61 formed with a follower (38 which entersthe cam-groove 69 in the usual teed-wheel 70. l

oi the well known type including" lower and upper elam 'nng members 71and 7]. partaking of longu udlnal and lateral, components of motionthrough suitable connections with the feedwheel.

- I lathe modification of theinvention shown .in' l i'n's. 5 and (l theledger-blade 72 formed with an inclined and Sharp cutting edge73 IS letInto the rih'Tlat the turret; said llireaddnuulling implements bo innmounted on said turret for cooperation o with} said needle and includinga loop-rein I-l tainerfulcrinnedto turn upon and relatively to saidrock-shaft. a thread-cutter mounted [,on saidturret.actuatingconnections between said roclosha ft andthread-mittenand means for actuat ng said rock-shaft at tliee-nd of thestitching operation.

.2. In a sewing machine, in combination, stitch lul'llllllgjlllttfllzllllslln including a reciprecating needle and cooperatingthreadhandling implements, lneann ineluding a "1oia'ry turret tor tlling said stit'elrformn'igmechanism in stitehing around the end of a'nnplehuttonhole eaid "thread --handling ment's be ng mounted on sait'ltu'rretand in eluding a loop -retainer having afbealnfon seizlng a,needle-loop and detamiiigitforl subsequent entry by said needle,-- athreadcutting implement mounted on said turret, u1ea-ns for advancingsaid cutting implement direction of loop-seizing movement of Saiddetainer to insert it into the last 3 the exposed face HIS set forththe-nature of the inmachine, in coi'uhin'a tion,

needle-hoop held by said detainer, and

means for ret'acting said thread-cutter to cause it to sever theneedle-thread.

3. In a sewing n nichlne in combination, StIlClbfOlll'llng mechanism,means including a rotaryturret for turning said StltClkfOlll'h ingmechanisn'i in stitching around the end of a buttonho-le, a cuttenhladedetachabl y t'ulcrumed on Said turret and having inte grally formed geaiteeth, and a segment aet'uatoiwgear' mounted on said turret and meshingwith said gear-teeth.

-.i:. In a huttonhole sewing machiniaun combination, stitch-formingmechanism in cllu'ling a reciprocaiting needle, and complenient-al'loop'takingr means rotary supporting means; t'l'ierefor includingaturret sustaining said loe-p-tali'ingr means, a needle- ,guidecarriedby said turret, and a threaldpivot-ally mounted I on sa d cutter bladeneialle-guide.

5. In a sewing machine, in combination,

stitclefoi'niing mechanism, rotar) supporting"mans therefor including aturret, a thread-clitting blademounted on said turret' arul formert witha forwardly directed point and arearwardly directed and sharpenedcutting edge, andii'ieans for advancing and retracting,iiilthlllldii-d Clllitlllg blade to eause'tlie latter to first: enterthe needle-loop and to subseq'iu-zntly sever one lin'ih thereof.

' (i. ln a sewing machine, in combination, stitch-forming iilechanisin,rotary supportetop-motion for controlling the period of action ofthestitclpforming-Inecl1anisn'1, a

thread eutr'er mounted on said turret and tlrrezul-taztter' actuatingineans connected to said stopimotion' for causing the thread-cub ter tofirst enterandsubsequentlydraw back upon and sever the la stneedledoop.

a. In a eewing n1aeh1ne,'inconibinatlon,

stitch-forming meehanisni,' rotary supp0rting n'iea'ns thereforincludingaturret, a

stop-motionforeontrol-ling 'the period of ac. tion ofthe h-fornnngmechanism, said i stop-nuition' neludingga Spr ng-pressed stopplug toothand a dri ven element formed with a stop-notch, a thread-cutterniountedon said turret, r and thread-cutter;- actuat ng meansyconnee'ted to axial Stopping tooth for caus-' in mg" the thread-cutterto ifirst; enter and then d aw back upon; and sevfer the. last needle-'loop.

In testimony where' fl h v ig my n'ameto this speeifie atigm. v i@ALEREB REX- 00D.

ing InCilllSl-llGl'G fOI including a turret, a

